textproduct: Quad Cities

KEY MESSAGES

- Slowly decreasing humidity will continue today until a secondary front moves through late this afternoon speeding up the process. Northwest winds gusting up to 30 mph should continue to push most of the wildfire smoke out of the area.

- Much cooler and less humid conditions will be seen the remainder of the work week before heat and humidity return for the weekend.

- Mainly dry conditions over the next 7 days as rain chances are quite low.

SHORT TERM /THROUGH TONIGHT/

Issued at 153 AM CDT Tue Jul 21 2026

Through sunrise, scattered showers and possibly a thunderstorm will be seen as the cold front sweeps through the area.

Windy, cooler but humid conditions will be seen across the area during the daylight hours. Deep mixing occurring behind the cold front should allow winds to gust up to 30 mph. The strong northwest winds should push most of the wildfire smoke out of the area.

Humidity levels will begin dropping around sunset as a secondary front moves through the area. Winds will also diminish as the boundary layer decouples.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 153 AM CDT Tue Jul 21 2026

Wednesday through Thursday night Assessment...a certainty of cooler and less humid conditions

Wednesday and Thursday will be banner days with cooler temperatures and dew points in the 50s.

The models have trended stronger with the high over the western Great Lakes which has now resulted in Thursday night being dry. This stronger high has ramifications for rain chances Friday

Friday Assessment...low (<20%) confidence on rain chances

The global models have now confined any rain chances on Friday to the morning hours. Dprog/Dt shows the system further south than yesterday which is a result of the high in the western Great Lakes being stronger.

The deterministic model runs (save the GFS) are dry for Friday. However, there are some ensemble members from each global model that have rain chances across the area Friday morning.

With the high stronger and the system further south in Missouri, the prospects for rain are not good. A review of the Integrated Vapor Transport shows the strongest values run from Oklahoma into southeast Kansas and southern Missouri. Thus while the model consensus currently has 15-35 percent rain chances Friday morning, I suspect these values will slowly drop over the next two days.

Friday night through Monday Assessment...medium to high (60-80%) confidence of rising humidity levels

Return flow develops across the Midwest starting Friday night and continues through the weekend as the heat dome builds north into the Plains. Dew points will slowly increase back into the low to mid 60s on Saturday with mid and upper 60 dew points Sunday into Monday. The combination of rising temperatures and dew points will eventually push heat indices into the 90s again.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 551 AM CDT Tue Jul 21 2026

Showers have moved southeast of all terminals of eastern Iowa and northwest Illinois as of 10Z. Clear skies with some scattered mid clouds are in the wake of the showers, with west winds at the surface around 8 kts this morning. A secondary front will arrive today, bringing winds to the northwest and with deepening mixing, gusty winds around 20-25kts can be expected through late afternoon. While initially mostly clear skies are expected, the cu-rule favors at least some broken cumulus/stratocumulus today north of I-80, but indications do suggest this will be VFR cigs. I have increase cloud cover in the CID and DBQ TAF through the afternoon hours for this, along with retaining VFR conditions.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.